Concrete Bags Per Cubic Yard — Full Reference Tables for All Bag Sizes

Concrete Bags Per Cubic Yard — Complete Reference Tables

One cubic yard equals 27 cubic feet. Every bag of pre-mixed concrete yields a fixed volume when water is added, and that yield divided into 27 gives you the bag count. That is the entire math. What takes time on site is cross-referencing the right bag size against the right volume while a pour is running and a crew is waiting.

This page eliminates that friction. It carries the full lookup tables for every standard bag size (40, 50, 60, and 80 lb plus 20 kg metric), fractional-yard counts from ¼ yd³ to 1½ yd³, an extended 0.25–5.0 yd³ table for larger pours, a project-type quick chart with pre-calculated bag counts for common jobs, a bag-size selection guide, and a clear decision rule for when bagged mix stops being the right choice.

The Bags-per-Yard Formula

Bags per yard = 27 ÷ Yield per bag (ft³)

Once you know a bag's yield, divide 27 by that number and you have the bags-per-yard rate. Standard yields from QUIKRETE and SAKRETE manufacturer data:

Bag Weight	Yield (ft³)	Bags per Cubic Yard
40 lb	0.30	90
50 lb	0.375	72
60 lb	0.45	60
80 lb	0.60	45
20 kg (metric)	0.33	82

Important: Always verify the yield printed on the specific bag you are purchasing. Specialty mixes — fiber-reinforced, fast-setting, high-strength — often yield 10–15% less than general-purpose bags of the same weight because they contain more cement per pound. A 45-per-yard rate that is accurate for a general-purpose 80 lb bag can be wrong by 5 bags per yard for a high-strength variant.

Fractional-Yard Quick Chart

Small pours rarely land on a round cubic-yard number. Use this table to read bag counts directly for common fractional volumes without multiplying.

Bag Weight	¼ yd³	½ yd³	¾ yd³	1 yd³	1½ yd³
40 lb	23	45	68	90	135
50 lb	18	36	54	72	108
60 lb	15	30	45	60	90
80 lb	11	23	34	45	68
20 kg	21	41	62	82	123

Round up to the next full bag — concrete pours do not stop at partial bags.

Tip for small pours (under ½ yd³): Fast-setting 50–60 lb bags are easier to handle and ideal for patching, fence posts, and column bases where speed matters.

Full Yards-to-Bags Lookup Table (0.25 to 5.0 yd³)

For pours from a small pad to a driveway or footing system, this table covers the full range where bagged concrete is practical. All values are rounded to the nearest whole bag — add 5–10% on top of what you read.

Cubic Yards	40 lb Bags	50 lb Bags	60 lb Bags	80 lb Bags
0.25	23	18	15	11
0.50	45	36	30	23
0.75	68	54	45	34
1.00	90	72	60	45
1.25	113	90	75	56
1.50	135	108	90	68
2.00	180	144	120	90
3.00	270	216	180	135
4.00	360	288	240	180
5.00	450	360	300	225

A 5% buffer on a 60-bag pour is only 3 extra bags, but it prevents an emergency hardware-store run mid-pour when the form is still open. Always carry the extra bags to the site, even if you expect not to need them.

This table works for general-purpose 3000–3500 psi mixes. Specialty mixes (fiber-reinforced, high-strength) may yield slightly less — always check the bag's data sheet and recalculate accordingly.

Worked Examples for Three Common Projects

Example 1 — Small Patio Slab (10 ft × 10 ft, 4 in thick)

Volume = 10 × 10 × 0.333 = 33.3 ft³ → 33.3 ÷ 27 = 1.23 yd³

Using the 1.25 yd³ row (round up to next entry):

80 lb bags: 56 bags → add 5% → 59 bags
60 lb bags: 75 bags → add 5% → 79 bags

At a crew mixing rate of ~45 bags per hour, this patio is a half-day pour for two workers. Choose 60 lb bags if anyone is lifting alone; 80 lb bags if you have a portable drum mixer.

Example 2 — Fence Posts (10 holes, 10 in diameter × 30 in deep)

Volume per hole = π × (0.417 ft)² × 2.5 ft ≈ 1.36 ft³
Total: 10 × 1.36 = 13.6 ft³ → 13.6 ÷ 27 = 0.50 yd³

From the ½-yard row:

80 lb bags: 23 bags
60 lb bags: 30 bags

Carry one extra bag per post as a buffer for over-excavated holes. For 10 posts: 30 of the 80 lb bags covers the pour and the buffer.

Example 3 — Garage Footings (2 ft wide × 1 ft thick × 40 ft total run)

Volume = 2 × 1 × 40 = 80 ft³ → 80 ÷ 27 = 2.96 yd³

Using the 3.00 yd³ row:

80 lb bags: 135 bags → add 8% for rough sub-base → 146 bags
60 lb bags: 180 bags → add 8% → 194 bags

At this volume — nearly 3 yards and over 11,000 lb of material — a short-load ready-mix truck is worth pricing before you commit to manual mixing. See the When to Switch to Ready-Mix section below.

Real-World Project Quick Reference

Pre-calculated bag counts for typical small concrete jobs. Volume is the placed concrete volume; bag counts use 80 lb bags with 5% waste already included.

Project	Typical Dimensions	Volume	80 lb Bags (+5% waste)
4×4 fence post (8 in dia × 24 in deep)	0.70 ft³ per hole	0.026 yd³	2 per hole
Deck pier (12 in dia × 36 in deep)	2.36 ft³ per pier	0.087 yd³	4–5 per pier
Small patio (10×10 ft × 4 in)	33.3 ft³	1.23 yd³	59 total
Driveway apron (12×12 ft × 5 in)	60 ft³	2.22 yd³	105 total
Shed floor (8×12 ft × 4 in)	32.1 ft³	1.19 yd³	57 total

For a larger structure, combine multiple sections. If your total comes to 3.5 yd³, you will need about 158 of the 80 lb bags (3.5 × 45 = 157.5, rounded up) before adding waste.

Choosing Your Bag Size

Bag size affects job flow, crew ergonomics, and total mixing time — not just the count on this table.

Bag Size	Pros	Cons	Best For
40 lb	Easy to lift alone, good for confined spaces	More bags to open, more store trips	Small patches, one-person jobs
50 lb	Common DIY size, moderate yield	Slightly higher count than 60 lb	General DIY, lighter-duty slabs
60 lb	Best balance of weight and yield	More demanding than 40/50 lb	Most patio and walkway pours
80 lb	Fewest bags, fastest batching	Heavy — needs two people or a mixer	Foundation pours, crew jobs, driveways
20 kg (metric)	Standard in UK, AU, CA	Yield varies by brand — check label	Any project in metric-standard markets

For hand-mixed jobs without a drum mixer, most experienced contractors prefer 60 lb bags. For crew jobs using a portable mixer, 80 lb bags cut total bag-opening cycles by 25% compared to 60 lb bags.

When to Switch to Ready-Mix

Bagged concrete's advantage is convenience on small pours — no truck minimum, no scheduling window, immediate start. Past a certain volume that advantage reverses.

Total Volume	Recommended Method	Reason
Up to 1 yd³	Bagged concrete	Manageable labor, low setup
1–2 yd³	Bagged or small mixer truck	Compare bag cost + labor vs. short-load delivery fee
2–3 yd³	Consider ready-mix	90–135 of the 80 lb bags is a full day of manual lifting
Over 3 yd³	Ready-mix delivery	Faster, more consistent, cheaper per yard at scale

The math at 3 yards: 135 bags of 80 lb mix weighs 10,800 lb of dry material. A ready-mix truck pours the equivalent in minutes at roughly $120–$ 170 per yard plus delivery. For most jobs above 2 yards, call the plant and price the truck before committing to bags.

Common Mistakes

1. Using the standard yield for specialty bags. Fast-setting and high-strength 80 lb bags often yield 0.55 ft³ or less per bag — not the standard 0.60 ft³. If you apply the standard 45-per-yard rate, you are short by about 5 bags per yard without knowing it.

2. Skipping the waste buffer. Subgrade roughness, over-excavation, and mixing losses consistently consume 5–10% more concrete than a clean geometry calculation predicts. Rounding up and adding 5% is standard practice, not over-ordering.

3. Switching bag sizes mid-pour. Mixing 60 lb and 80 lb bags mid-project breaks your counting rhythm and leaves you unsure how much volume you have placed. Decide on one bag size per pour and stick to it.

4. Confusing cubic yards and cubic feet. One cubic yard is 27 cubic feet — not 3. This mistake shows up when someone tries to do the bags-per-yard math quickly in their head and divides by the wrong number.

Pro Tips from Site Practice

Stage bags before the pour. Count out your total, group in stacks of 10 near the mixer, and pace the pour by watching the stacks count down.
Read the yield line on every bag. The printed yield per bag is the number that feeds every table on this page — check it before you finalize your order.
Check expiration dates. Bags stored more than 3–4 months in a humid environment lose cement reactivity. Test for clumping before opening the first bag of old stock.
Keep mixing water consistent. Adding extra water to make mixing easier is the fastest way to produce concrete below its rated strength. Use the water ratio on the label every time.
Run the calculator before you buy. The Bags-per-Yard Concrete Calculator outputs all four bag sizes simultaneously for any volume — paste the result into your shopping list and print it for the store.

Visit Concrete Calculator Max for the full library of concrete calculators and estimation tools.

Conclusion

One cubic yard requires 45 bags of 80 lb mix, 60 bags of 60 lb, 72 bags of 50 lb, or 90 bags of 40 lb. Use the fractional-yard chart for small pours under 1½ yd³, the full lookup table for anything from a quarter yard to five yards, and always add 5–10% for real-world waste.

If your volume climbs past two yards, price a ready-mix truck before committing to manual mixing — the crossover where bagged concrete becomes the harder, more expensive option is lower than most people expect.

For instant bag counts across all four standard sizes at once, use the Bags-per-Yard Concrete Calculator — enter any volume in yd³ or ft³ and read the full breakdown in one step, including pallets needed for delivery planning.

Concrete Bags Per Cubic Yard — Full Reference Tables for All Bag Sizes

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